Anticholinergics reduce intestinal movement and are effective against both diarrhoea and accompanying cramping.

Opioids‘ classical use besides pain relief is as an anti-diarrhoeal drug. Opioids have agonist actions on the intestinal opioid receptors, which when activated cause constipation. Drugs such as morphine or codeine can be used to relieve diarrhoea this way. A notable opioid for the purpose of relief of diarrhoea is loperamide which is only an agonist of the μ opioid receptors in the large intestine and does not have opioid affects in the central nervous system as it doesn’t cross the blood–brain barrier in significant amounts. This enables loperamide to be used to the same benefit as other opioid drugs but without the CNS side effects or potential for abuse.